1. Field of the Invention
The present invention relates to a vehicular lamp including a reflector formed by a translucent member.
2. Related Art
Most vehicular lamps include a light source disposed on an optical axis extending in the front-back direction of the lamp and a reflector that reflects forward light from the light source.
“Patent Document 1” and “Patent Document 2” describe such a vehicular lamp in which the reflector is formed by a translucent member.
In the reflector described in “Patent Document 1,” a surface of incidence is formed on a portion of the rear surface of the translucent member in the proximity of the optical axis so as to surround the light source. A plurality of reflective surfaces are formed on a portion of the rear surface of the translucent member around the surface of incidence so as to be stepped in the radial direction of the optical axis. Surfaces of emission are formed on the front surface of the translucent member in front of the respective reflective surfaces.
In the vehicular lamp described in “Patent Document 1,” light from the light source is incident into the translucent member forming the reflector through the surface of incidence, and internally reflected forward as generally parallel light by the reflective surfaces. The internally reflected light is then emitted forward through the surfaces of emission positioned in front of the reflective surfaces.
In the reflector described in “Patent Document 2,” a plurality of surfaces of incidence and surfaces of emission are formed on the front surface of the translucent member so as to be stepped in the radial direction relative to the optical axis, and the rear surface of the translucent member is formed as a single flat surface.
In the vehicular lamp described in “Patent Document 2,” light from the light source incident into the translucent member forming the reflector through each of the surfaces of incidence is internally reflected forward by the rear surface of the translucent member. The light is then emitted forward through the surfaces of emission positioned in front of, or on the outer circumferential side of, the reflective surface.
[Patent Document 1] Japanese Patent Application Laid-Open (Kokai) No. JP-A-2005-203111
[Patent Document 2] Japanese Patent Application Laid-Open (Kokai) No. 2004-126422